Probabilistic Miracles: Why Nothing in Nature is Physically Impossible

The physically impossible differs from the logically impossible. It’s logically impossible that 2 plus 2 equals 5 or that a bachelor is married. On the other hand, it’s physically impossible to build a perpetual motion machine or for a human at a high-jump competition to clear 100 feet. The Second Law of Thermodyanmics is supposed to bar the first of these. As for the second, given human size and strength in the earth’s gravitational field, jumping 8 feet seems about the limit — the world record, set by Javier Sotomajor in 1993, stands at eight feet and one-half inches:

But what if something physically impossible did happen? Would it be a miracle? It depends on what one means by a miracle. The Latin word from which we get our word miracle (miraculum) denoted an object of wonder. Bascially, a miracle is something that causes us to go Wow! But look at Javier Sotomajor’s world record jump in the YouTube video above, and you’ll probably also go Wow! Yet you probably don’t want to call that a miracle. Sotomajor, through his natural physical talents and diligent training, got his body into a condition where it could clear 8 feet.

So a miracle isn’t something that simply causes us to be surprised, shocked, or put in a state of awe or wonder. When we call something a miracle, we usually have in mind something that also goes beyond the limits of what’s physically possible. Thus it seems that we do want a miracle to mean an event that is physically impossible. Often this is put in terms of the laws of nature forbidding the event from happening. But if the laws of nature forbid an event from happening, then how can it happen? In fact, many skeptics think that miracles are inherently self-contradictory: if something is physically impossible, then it can’t happen, and so whatever happens is not a miracle; on the other hand, if it did happen, it wasn’t physically impossible, so it wasn’t a miracle.

But what is this thing we’re calling “physical impossibility”? We can certainly imagine the occurrence of events that are physically impossible (for example, we can imagine a machine that without external energy maintains its motion for 100 years nonstop or Javier Sotomajor jumping St. Louis’s Gateway Arch). Moreover, if we can imagine these events happening, can’t we also imagine ourselves witnessing them and thereby being compelled to think that something physically impossible did happen, in which case we would be agreeing that a miracle occurred? To say that something is physically possible is to say it is compatible with the ordinary way that nature operates. Physical impossibility would therefore seem to say that nature can’t operate extraordinarily. But why should nature be limited in that way?

Dawkins-Religion-PhotoThe only way to block nature from operating extraordinarily is to say that nature operates by unbreakable laws that constrain it down certain paths and prohibit it from others. But how do we know that unbreakable laws determine the ordinary operation of nature, and thus prohibit its extraordinary operation? The typical way that philosophers and scientists argue this is by claiming that matter obeys certain unbreakable laws governing its operation, and that nature is identical with a system of matter. But even this argument loses its force once we acknowledge that matter can behave probabilistically. Consider, for instance, the following characterization of miracles by Oxford biologist and atheist Richard Dawkins:

What do we mean by a miracle? A miracle is something happens, but which is exceedingly surprising. If a marble statue of the Virgin Mary suddenly waved its hand at us we should treat it as a miracle, because all our experience and knowledge tells us that marble doesn’t behave like that… [This occurrence would not] be classified by science as utterly impossible… In the case of the marble statue, molecules in solid marble are continuously jostling against one another in random directions. The jostlings of the different molecules cancel one another out, so the whole hand of the statue stays still. But if, by sheer coincidence, all the molecules just happened to move in the same direction at the same moment, the hand would move. If they then all reversed direction at the same moment the hand would move back. In this way it is possible for a marble statue to wave at us. It could happen. The odds against such a coincidence are unimaginably great but they are not incalculably great. [Richard Dawkins, The Blind Watchmaker, pp. 159–160.]

Marble_Statue_of_Virgin_MaryIf marble statues waving at us pose no more than a probabilistic obstacle for nature (rather than an insurmountable barrier), why should we think that anything is physically impossible? Indeed, it seems that what we are calling physical impossibility is really just extreme improbability, or what we might call a probabilistic miracle. Now it might seem that the difference between physical impossibility and probabilistic miracle is purely semantic, an academic argument about the nuances of words. But in fact there is a big difference here. To call something physically impossible but then turn around and say that this just means it’s extremely improbable is to speak out of both sides of one’s mouth. Impossibility implies an absolute prohibition — it can’t happen. Improbability, even if extreme, implies not an absolute prohibition but something that, though unlikely, could nevertheless happen and even become likely if given enough opportunities to occur.

So what would you think if a marble statue waved at you or if some other fantastically improbable event were to happen and you were to witness it? How would you interpret such an event? Would you merely think that some vastly improbable fluke had happened? Or would you think that a supernatural force beyond nature was trying to get your attention? Over 50 years ago, C. S. Lewis wrote an interesting book titled Miracles. In it he says he knows only one person who has seen a ghost, but then adds that this person doesn’t believe in ghosts. Lewis’s point was that if one’s worldview has no place for ghosts, then even if one sees a ghost, one won’t believe they exist. Miracles pose this same challenge. Is something a miracle because a supernatural being produced it? Or is it a miracle because some vastly improbable event occurred?

anatole_franceProbabilistic miracles, whether caused by a supernatural being or resulting from a fluke of nature, raise a problem for those who want to exclude miracles outright. Rather than admit that a probabilistic miracle has occurred, they will want to argue that we got the probabilities wrong and so the miracle wasn’t really a miracle after all. Consider the following 100-year-old quote from the French skeptic Anatole France:

Happening to be at Lourdes [a famous Catholic shrine where miracles of healing are said to have happened], in August, I paid a visit to the grotto where innumerable crutches were hung up in token of a cure. My companion pointed to these trophies of the sick-room and hospital ward, and whispered in my ear: “One wooden leg would be more to the point.” It was the word of a man of sense; but speaking philosophically, the wooden leg would be no whit more convincing than a crutch. If an observer of a genuinely scientific spirit were called upon to verify that a man’s leg, after amputation, had suddenly grown again as before, whether in a miraculous pool or anywhere else, he would not cry: “Lo! a miracle.” He would say this: “An observation, so far unique, points us to a presumption that under conditions still undetermined, the tissues of a human leg have the property of reorganizing themselves like a crab’s or lobster’s claws and a lizard’s tail, but much more rapidly. Here we have a fact of nature in apparent contradiction with several other facts of the like sort. The contradiction arises from our ignorance, and clearly shows that the science of animal physiology must be reconstituted, or to speak more accurately, that it has never yet been properly constituted. [Quoted from The Garden of Epicurus.]

Thus, for Anatole France, a leg growing back would not be treated as a probabilistic miracle (as with a thermodynamic accident in which material particles randomly converged on the maimed limb and restored it), but as a rationally explainable event subject to laws of physiology that for now we don’t quite understand. In other words, in place of a probabilistic miracle, France would plead ignorance of the underlying science, which, if known, would show that nothing too improbable had in fact happened.

Mind_and_Cosmos_coverThis strategy for defeating probabilistic miracles works for those who find them inconvenient to their worldview. The point to recognize, however, is that it is a strategy. Probabilistic miracles, if they happen, require a response, even from skeptics. Nor does one have to be religious to be convinced of probabilistic miracles. Well-known philosopher Thomas Nagel, for instance, has recently written Mind & Cosmos, in which he regard the origin of life as a “probabilistic miracle” (he uses that exact phrase) if one treats nature as inherently without teleology or intelligence. Thus the subtitle of that book reads: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False.

Take home lesson: When it comes to trying to understand if there’s something outside of nature, the real issue is not physical impossibility but extreme improbability. In a probabilistic universe, there is no physical impossibility. In such a universe, there could, however, be probabilistic miracles. Whether we think they have happened and how we make sense of them depends very much on our worldview.